DTC P0234:00 [PCM (SKYACTIV-G 2.5T)]

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Note
•  To determine the malfunctioning part, proceed with the diagnostics from “Function Inspection Using M-MDS”.

Details On DTCs

DESCRIPTION

Dynamic pressure turbo (DPT) overboost condition
DETECTION CONDITION
Determination conditions
•  As the result of comparing the actual air charging pressure with the limited pressure, the actual air charging pressure exceeds the limited air charging pressure for a continuous 2 s.
Preconditions
•  2 s have elapsed with all of the following conditions met when DPF regeneration control is stopped during boost control feedback.
?  Engine speed: 500 rpm or more
?  The following DTCs are not detected:
•  Boost pressure sensor: P0237:00, P0238:00
•  BARO sensor: P2228:00, P2229:00
Drive cycle
•  2
Self test type
•  CMDTC self test
Sensor used
•  MAP sensor
FAIL-SAFE FUNCTION
•  Limits intake air amount. (Only period of time when PCM determines that air is excessively boosted)
VEHICLE STATUS WHEN DTCs ARE OUTPUT
•  Not applicable
POSSIBLE CAUSE
•  Erratic signal to PCM
?  MAP sensor signal malfunction
?  Input signal part connector or terminals malfunction
?  Input signal part related circuit malfunction
•  Vacuum piping or positive pressure piping of wastegate valve actuator malfunction
•  Air bypass valve malfunction
•  Wastegate valve position sensor malfunction
•  Wastegate valve actuator malfunction
•  Dynamic pressure turbo (DPT) malfunction
•  PCM malfunction

System Wiring Diagram

•  Not applicable

Function Explanation (DTC Detection Outline)

•  The PCM diagnoses the turbo system performance by comparing the target air charging pressure with the actual.
•  The PCM uses the manifold absolute pressure sensor to monitor the intake manifold pressure during boost control as the actual air charging pressure.
•  When the monitoring conditions are met during boost control, the PCM compares the target air charging pressure with the actual. If the actual air charging pressure is higher than the specification for the target air charging pressure, the PCM determines an excess air charging malfunction.
•  The PCM performs diagnosis when each of the preconditions during drive cycle is met. If a malfunction is detected, the malfunction detection counter begins counting up. The value of the malfunction detection counter is maintained while the preconditions are not being met. If the cumulative value of the malfunction detection counter exceeds the threshold during the first drive cycle, a malfunction is determined and a pending code is stored.
•  If the PCM determines that the malfunction recurs from the next drive cycle and thereafter, it stores a DTC.
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Repeatability Verification Procedure

Caution
•  When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
•  While performing this step, always operate the vehicle in a safe and lawful manner.
1.  Access the following PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.5T)].)
?  MAP_DSD
?  MAP
2.  Start the engine and warm it up completely.
3.  Shift to 2nd gear and rapidly accelerate the vehicle to 40 km/h {25 mph}.
4.  Accelerate in 2nd gear from 40 km/h {25 mph} to 55 km/h {35 mph} for 5 s or more.
5.  Verify that the difference between MAP_DSD and MAP during acceleration is less than 70 kPa {0.71 kgf/cm2, 10 psi}.

PID Item/Simulation Item Used In Diagnosis

PID/DATA monitor item table

Item

Definition

Unit

Condition/Specification
MAP
Manifold absolute pressure input from MAP sensor
KPa {MPa}, mBar {Bar}, psi, in H20
•  Displays MAP
MAP_V
MAP sensor voltage
V
•  Ignition switched ON (engine off) (no load) (MAP: 102 kPa {1.04 kgf/cm2, 14.8 psi}): Approx. 1.75 V
•  Idle (after warm up) (no load) (MAP: 30 kPa {0.31 kgf/cm2, 4.4 psi}): Approx. 0.68 V
•  Racing (engine speed is 2,000 rpm) (no load) (MAP: 27 kPa {0.28 kgf/cm2, 3.9 psi}): Approx. 0.61 V


Function Inspection Using M-MDS

STEP

INSPECTION

ACTION
1
PURPOSE: RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION
Note
•  Recording can be facilitated using the screen capture function of the PC.
•  Record the snapshot data on the repair order.
—
Go to the next step.
2
PURPOSE: VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
PURPOSE: IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA
•  Is the DTC P0234:00 on FREEZE FRAME DATA?
Yes
Go to the next step.
No
Go to the troubleshooting procedure for DTC on FREEZE FRAME DATA.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
4
PURPOSE: VERIFY IF DIAGNOSTIC RESULT IS AFFECTED BY OTHER RELATED DTCs OCCURRING
•  Switch the ignition off, then ON (engine off).
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Is the other PENDING CODE/DTC also present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
No
Go to the next step.
5
PURPOSE: VERIFY IF THERE IS PID ITEM CAUSING DRASTIC CHANGES OF ACCELERATION FLUCTUATION BY INPUT SIGNAL TO PCM
•  Access the following PIDs using the M-MDS:
PCM:
?  MAP
?  MAP_V
•  Is there any signal that is far out of specification?
Yes
Go to the next step.
No
Go to the troubleshooting procedure to perform the procedure from Step 1.
6
PURPOSE: VERIFY CONNECTOR CONNECTIONS
•  Access the following PIDs using the M-MDS:
PCM:
?  MAP
?  MAP_V
•  When the following parts are shaken, does the PID value include a PID item which has changed?
?  MAP sensor
?  PCM
Yes
Repair or replace the applicable connector parts.
Go to the troubleshooting procedure to perform the procedure from Step 5.
No
Go to the troubleshooting procedure to perform the procedure from Step 1.

Troubleshooting Diagnostic Procedure

Intention of troubleshooting procedure
•  Step 1—4
?  Perform inspection of each separate part.
•  Step 5—6
?  Verify that the primary malfunction is resolved and there are no other malfunctions.

STEP

INSPECTION

ACTION
1
PURPOSE: INSPECT AIR BYPASS VALVE
•  Inspect the air bypass valve.
•  Is there any malfunction?
Yes
Replace the dynamic pressure turbo (DPT), then go to Step 5.
(See DYNAMIC PRESSURE TURBO REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
No
Go to the next step.
2
PURPOSE: INSPECT WASTEGATE VALVE POSITION SENSOR
•  Inspect the wastegate valve position sensor.
•  Is there any malfunction?
Yes
Replace the dynamic pressure turbo (DPT), then go to Step 5.
(See DYNAMIC PRESSURE TURBO REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
No
Go to the next step.
3
PURPOSE: INSPECT WASTEGATE VALVE ACTUATOR
•  Inspect the wastegate valve actuator.
•  Is there any malfunction?
Yes
Replace the dynamic pressure turbo (DPT), then go to Step 5.
(See DYNAMIC PRESSURE TURBO REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
No
Go to the next step.
4
PURPOSE: INSPECT DYNAMIC PRESSURE TURBO (DPT)
•  Inspect the dynamic pressure turbo (DPT).
•  Is there any malfunction?
Yes
Replace the dynamic pressure turbo (DPT), then go to the next step.
(See DYNAMIC PRESSURE TURBO REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
No
Go to the next step.
5
PURPOSE: PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING PART IS PCM
•  Always reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Implement the repeatability verification procedure.
•  Perform the Pending Trouble Code Access Procedure.
•  Is the PENDING CODE for this DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
6
PURPOSE: VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
No
DTC troubleshooting completed.